In general, microactuators permit an optical fiber to be aligned with an electro-optic device, such as a laser diode or even another optical fiber. Such alignment is particularly desirable for maximizing the percentage of light coupled from the light source (i.e., the electro-optic device) to the optical fiber. In turn, this increases the transmission efficiency of the optical signals. However, the relatively small sizes of both the optical fiber waveguide and the light source complicates the alignment of optical fibers. For example, a typical single mode optical fiber has a light transmitting core diameter of approximately 2 to 10 .mu.m and a suitable light source is usually about the same size.
Commonly assigned U.S. Pat. No. 5,602,955, the entire disclosure of which is incorporated herein by reference, describes various methods and apparatus known in the art for aligning an optical fiber as well as the shortcomings associated with those methods and apparatus. For example, one known method includes aligning the fiber and bonding it in place with solder or some other bonding agent. Such bonding typically requires heating the bonding agent while the fiber is being aligned and then allowing the bonding agent to cool. Unfortunately, heating in this manner often causes misalignment of adjacent optical fibers. U.S. Pat. No. 5,602,955 shows a microactuator which controllably positions an optical fiber without the need for heating during alignment thereby preventing misalignment of adjacent optical fibers.
This patent further overcomes conventional alignment and bonding systems and methods which are generally relatively laborious and time-intensive, particularly in instances in which a number of optical fibers must be individually aligned, and require a variety of relatively complex and costly components which significantly increase the fabrication costs to produce such precisely aligned optical devices.
In addition, the microactuator of U.S. Pat. No. 5,602,955 precisely aligns an optical fiber within a hermetically sealed package, such as a standard 14-pin hermetic butterfly package, in which opto-electronic devices are typically disposed.
Although the microactuator of U.S. Pat. No. 5,602,955 provides a significant improvement over the existing art, further improvements are desired for providing a microactuator which is internally referenced so that it returns to an equilibrium, unenergized position without the need for an external alignment support structure, or well, or external counteract springs. In addition, U.S. Pat. No. 5,602,955 discloses a microactuator fabricated with bimorphic actuators. Therefore, it is also desired to fabricate a microactuator which provides for movement in at least two directions without bimorphic actuators to simplify construction.